RU2475941C1 - Differential amplifier with complementary input cascade - Google Patents

Abstract

FIELD: radio engineering, communication.SUBSTANCE: differential amplifier with a complementary input cascade comprises the first (1) and second (2) inputs of the device, the first (3) input transistor, the collector of which is connected with the first (4) bus of the power supply source via the first (5) current-stabilising dipole and is connected with the base of the first (6) output transistor, the second (7) input transistor, the collector of which is connected with the first (4) bus of the power supply source via the second (8) current-stabilising dipole and is connected with the base of the second (9) output transistor, the third (10) input transistor, the emitter of which is connected with the emitter of the first (3) input transistor, the fourth (11) input transistor, the emitter of which is connected with the emitter of the second (7) input transistor, the third (12) current-stabilising dipole, connected between the emitter of the second (9) output transistor, the fourth (15) current-stabilising dipole, connected between the emitter of the first (6) output transistor. Between the first (13) and second (16) outputs of the device there are serially connected the first (17) and second (18) additional resistors, besides, the common unit of the first (17) and second (18) additional resistors is connected with combined bases of the first (3) and second (7) input transistors via the additional non-inverting amplifier (19).EFFECT: provision of high stability of a static mode of a differential amplifier and higher value of its amplification ratio by voltage.8 dwg

Description

The invention relates to the field of radio engineering and communication and can be used as a device for amplifying analog signals in the structure of analog microcircuits for various functional purposes, for example, decision amplifiers, comparators, bridge power amplifiers, etc.

Known circuits of classical differential amplifiers (DU) with a complementary input stage, which became the basis of many serial analog circuits [1-11].

In addition, the remote controls of this class are actively used in the structure of microwave devices implemented on the basis of SiGe technologies. This is due to the possibility of building on their basis active RC-filters of the gigahertz range for modern and promising communication systems, bridge power amplifiers, etc.

The closest prototype (figure 1) of the claimed device is a differential amplifier described in US patent 3828268, fig.5, containing the first 1 and second 2 inputs of the device, the first 3 input transistor, the collector of which is connected to the first 4 bus power supply through the first 5 current-stabilizing bipolar and connected to the base of the first 6 output transistor, the second 7 input transistor, the collector of which is connected to the first 4 bus power supply through the second 8 current-stabilizing bipolar and connected to the base of the second 9 output transistor a, the third 10 input transistor, the emitter of which is connected to the emitter of the first 3 input transistor, the fourth 11 input transistor, the emitter of which is connected to the emitter of the second 7 input transistor, the third 12 current-stabilizing two-terminal connected between the emitter of the second 9 output transistor, connected to the first 13 output the device and the second 14 bus power supply, the fourth 15 current-stabilizing two-pole connected between the emitter of the first 6 output transistor associated with the second 16 output of the device and the second 14 w another power source, and the collectors of the first 6 and second 9 output transistors are connected to the first 4 bus of the power source, and the collectors of the third 10 and fourth 11 input transistors are connected to the second 14 bus of the power source.

A significant drawback of the known control is that it is not efficient due to problems with static mode at high voltage gain (K _v) which depends on the resistances of the first 5 and the second 8 tokostabiliziruyuschih-ports, which may for larger K _have performed in form of current sources.

The main objective of the invention is to create conditions under which high stability of the static mode of the remote control and increased values of its voltage gain are ensured.

The problem is solved in that in the differential amplifier of figure 1, containing the first 1 and second 2 inputs of the device, the first 3 input transistor, the collector of which is connected to the first 4 bus power supply through the first 5 current-stabilizing two-terminal device and connected to the base of the first 6 output transistor, the second 7 input transistor, the collector of which is connected to the first 4 bus of the power supply through the second 8 current-stabilizing two-terminal network and connected to the base of the second 9 output transistor, the third 10 input transistor, the emitter of which o connected to the emitter of the first 3 input transistor, the fourth 11 input transistor, the emitter of which is connected to the emitter of the second 7 input transistor, the third 12 current-stabilizing two-terminal connected between the emitter of the second 9 output transistor connected to the first 13 output of the device and the second 14 bus of the power source, the fourth 15 current-stabilizing two-terminal connected between the emitter of the first 6 output transistor associated with the second 16 output of the device and the second 14 bus power source, and the collectors of the first 6th and second 9th output transistors are connected to the first 4 bus of the power supply, and the collectors of the third 10th and fourthth 11th input transistors are connected to the second 14th bus of the power supply, new elements and communications are provided - the first 1 input of the device is connected to the base of the third 10th input transistor, the second 2 input of the device is connected to the base of the fourth 11 input transistor, between the first 13 and second 16 outputs of the device connected in series are the first 17 and second 18 additional resistors, and the common node of the first 17 and second about 18 additional resistors connected to the bases of the first joint 3 and second input transistors 7 via an additional non-inverting amplifier 19.

In Fig.1 shows a diagram of the remote control prototype.

Figure 2 shows a diagram of the inventive device in accordance with the claims.

Figure 3 presents the diagram of figure 2 with the specific implementation of the additional non-inverting amplifier 19 for the case when the input voltage u _I.1 , u _I.2 are supplied to the inputs of the remote control relative to the common bus.

Figure 4 presents the diagram of figure 2 with the specific implementation of the additional non-inverting amplifier 19 for the case when the input voltage u _I.1 , u _I.2 are supplied to the inputs of the remote control relative to the second 14 negative bus power source.

Figure 5 shows a diagram of the claimed remote control of figure 3 in the environment of computer simulation PSpice on models of integrated transistors of FSUE NPP Pulsar.

In Fig.6 shows the frequency dependence of the gain on the voltage of the remote control of Fig.5.

In Fig.7 shows the voltage at the outputs of the remote control of Fig.5 with an input signal Uin = 1 mV and f = 1 MHz, and Fig.8 - voltage at the outputs with an input signal Uin = 3 mV and f = 1 MHz.

The differential amplifier with a complementary input stage of figure 2 contains the first 1 and second 2 inputs of the device, the first 3 input transistor, the collector of which is connected to the first 4 bus power supply through the first 5 current-stabilizing two-terminal device and connected to the base of the first 6 output transistor, the second 7 input transistor , the collector of which is connected to the first 4 bus of the power source through the second 8 current-stabilizing bipolar and connected to the base of the second 9 output transistor, the third 10 input transistor, the emitter of which is connected is connected with the emitter of the first 3 input transistor, the fourth 11 input transistor, the emitter of which is connected to the emitter of the second 7 input transistor, the third 12 is a current-stabilizing two-terminal connected between the emitter of the second 9 output transistor connected to the first 13 output of the device and the second 14 bus of the power source, fourth 15 current-stabilizing two-terminal connected between the emitter of the first 6 output transistor associated with the second 16 output of the device and the second 14 bus power source, and the collectors of the first 6 and the second 9 output transistors are connected to the first 4 bus of the power source, and the collectors of the third 10 and fourth 11 input transistors are connected to the second 14 bus of the power source. The first 1 input of the device is connected to the base of the third 10 input transistor, the second 2 input of the device is connected to the base of the fourth 11 input transistor, between the first 13 and second 16 outputs of the device are connected in series the first 17 and second 18 additional resistors, and the common node of the first 17 and second 18 additional resistors are connected to the combined bases of the first 3 and second 7 input transistors through an additional non-inverting amplifier 19.

As transistors 6 and 9, classic composite transistors can be used, including resistors or pn junctions 24, 25, 27, 28 in emitter circuits. In the circuit of Fig. 3, these composite transistors 6 and 9 are made on the elements 23, 24, 25 and 26, 27, 28. An additional non-inverting amplifier 19 in the circuit of Fig. 3 is implemented on the transistor 20, the resistor 21, and the current source 22.

In the circuit of FIG. 4, an additional non-inverting amplifier 19 contains an input transistor 29 and a matching resistor 30. With this construction of the remote control, the coordination of the static modes of transistors 3, 7, 10, 11, 9, and 6 is greatly simplified.

Consider the operation of the remote control of Fig.3.

The static current mode of the transistors of the proposed remote control of figure 2 is set by the current-stabilizing two-terminal 5, 8, 12, and 15. Moreover, the collector (I _ki ) currents of the transistors of the circuit:

where I ₀ is the set value of the reference current, for example 1 mA.

Static voltages at the outputs of the remote control at a zero input signal (u _in = 0) depend only on the voltage U ^(-) at the inverting input of the additional amplifier 19:

Moreover, the collector-base voltage of transistors 3 and 7, which determine the amplitude (U _m ) of the output voltage of the remote control:

where U _{eb. Σ.9} , U _{eb. Σ.6} are the emitter-base voltages of transistors 9 and 6, which, in order to ensure the given output amplitudes U _m in the circuit of Fig. 3, must be implemented as composite active elements or CMOS transistors. In the diagram of FIG. 4, such a construction of 9 and 6 is optional;

U _eb. 3 _≈U eb. ₇ ≈U _eb. 10 _≈U eb. ₁₁ ≈0.7 V - emitter-base voltage of transistors 3, 7, 10, 11.

Thus, the static mode of the transistors of the circuit of figure 2 does not depend on the differential resistance (r _i = r _i5 = r _i8 ) of the two-terminal 5, 8, which to increase K _y to a level of 60 ÷ 70 dB (figure 6) can be performed in the form current sources. In the remote control prototype of figure 1, such a design of elements 5, 8 is not acceptable due to problems with the stability of the static mode. Increased values of r _i = r _i5 = r _i8 allow to obtain increased values of K _y in the scheme of figure 2.

The results of computer simulation of the circuit of Fig. 5 show that based on the proposed remote control, broadband drivers of differential communication lines are used for power amplifiers, phase shifters with increased gain, etc.

BIBLIOGRAPHIC LIST

1. Patent application US No. 2010/0225392.

2. US patent No. 3786362.

3. US patent No. 3828268.

4. US patent No. 5406222.

5. US patent No. 3555402.

6. US patent No. 4074205.

7. US patent No. 5401995.

8. Patent SU No. 1107279.

9. JP patent No. 57-5364.

10. US patent No. 4/030/044.

11. US patent No. 4/286/227.

Claims (1)

A differential amplifier with a complementary input stage containing the first (1) and second (2) inputs of the device, the first (3) input transistor, the collector of which is connected to the first (4) bus of the power source through the first (5) current-stabilizing two-terminal device and connected to the base of the first (6) an output transistor, a second (7) input transistor, the collector of which is connected to the first (4) bus of the power supply through a second (8) current-stabilizing two-terminal device and connected to the base of the second (9) output transistor, the third (10) input transistor, emitter koto it is connected to the emitter of the first (3) input transistor, the fourth (11) input transistor, the emitter of which is connected to the emitter of the second (7) input transistor, the third (12) current-stabilizing two-terminal connected between the emitter of the second (9) output transistor connected to the first (13) the output of the device and the second (14) bus of the power source, the fourth (15) current-stabilizing two-terminal connected between the emitter of the first (6) output transistor connected to the second (16) output of the device and the second (14) bus of the power source, the collectors of the first (6) and second (9) output transistors are connected to the first (4) bus of the power source, and the collectors of the third (10) and fourth (11) input transistors are connected to the second (14) bus of the power source, characterized in that the first (1) the input of the device is connected to the base of the third (10) input transistor, the second (2) input of the device is connected to the base of the fourth (11) input transistor, the first (17) connected in series between the first (13) and second (16) outputs of the device and the second (18) additional resistors, and the common node th (17) and second (18) additional resistors associated with the combined bases of the first (3) and second (7) input transistors via a further inverting amplifier (19).

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